Typically, we used the present perfect to emphasize that something has happened, regardless of when it occurred. We say things like "I have been to Canada" when the important thing is whether the action has happened, not when it happened.

Present perfect continuous emphasizes time to a much greater extent. If you say "I have been touring Canada" you imply that you have just stopped doing that -- there is a definite element of time that is present in this structure.

I've always been puzzled by blanket attempts to explain the difference between these verbal constructions. I taught at the university level in Germany for four years or so and, even among the students who spoke amazingly good English, heard all sorts of constructions using the perfect and perfect progressive that just sounded wrong to me, but I was at a complete loss as to why.

For me, to respond to the example of the previous poster, the sentence "I have been touring Canada" does not imply that the tour has just ended. Rather, it implies that the tour is ongoing. "I have toured Canada" is (again, to me) much more likely to suggest that the tour is over.

Examples are probably the best way to go. Here's a sample Q&A that sounds natural enough to me:

Q: How's your winter been? Any chance you'll come to visit?

A: Cold. I've been touring Canada and shoud be back in town next week. I'll call you then.

Here's another:

Q: Have you ever been to Canada?

A: Yes. I have toured Canada three times. Last summer was the most recent time.

I'd be very interested in hearing how other people make sense of what these different constructions are used for.

Since the word perfect is Latin and denotes completion, there is definitely a completion of action in the Basic Form of the present perfect tense. For instance, when a student tells the teacher, "I have finished my work," the student expresses the fact that he/she has begun the work in a past time, but the work is now (present) finished. or completed. Therefore, there is continuity ONLY from the past initiation of the action up to the present in which it is completed, or perfected, with the use of the Present Perfect Tense. The action is NOT continuing.

When the Progressive Form of the Present Perfect Tense is employed, there is the implication that the action is ongoing, but will soon (present) be completed. In the example "I have been touring Canada," the speaker means that he/she has started touring in the recent past and is continuing in the present time, rather than being finished in the present time.

Certain dialects confuse these grammatical rules in their usage. For instance, in Ireland and in the Irish neighborhoods of New York, Boston, and Chicago, it was not unusual some years ago to hear many speakers employ the Progressive Form (-ing) when the Basic Form should be used. Many Scot-Irish descendants in the South still use this construction, also.

In response to mwestwood's comment, I agree that many dialects--and also those of non-native speakers--confuse grammatical rules and their usage, particularly the difference between Basic and Progressive Forms.

For example, I teach 12th grade English at a bilingual school in Honduras. Many students are good at speaking English, but have trouble with verb tenses, as in the following sentence:

"Miss! Ricardo is bothering!"

What the student really means is:

"Miss! Ricardo bothers me!" or even "Miss! Ricardo is bothering me!"

I also find it interesting that these students generally use Simple Present Tense, even when talking about something they have doen in the past:

"Ricardo, how was your weekend?"

"Good. My cousin come over on Saturday."

I am not sure if this occurs because of their grasp of English is not as strong, or if it is because their teachers have told them to write in the present tense, and therefore they also speak the same way. I am very interested to hear what others have to say on this topic.